Interface reactions and mechanical properties of FeCrAl-coated Zircaloy-4

© 2019 Elsevier B.V. FeCrAl has been proposed as a coating layer to enhance accident tolerance of Zircaloy-4 fuel cladding. In this study, we systematically examined the diffusion kinetics and interface compound formation of the spray-coated FeCrAl and Zircaloy-4 substrate. After vacuum annealing at 923 K, 963 K, and 998 K for various time periods, a mixed Zr 2 Fe phase and Zr 3 Fe formed at the interface. The formation energies of these two phases were found to be 65 kJ/mol and 58 kJ/mol for Zr 2 Fe and Zr 3 Fe, respectively. Bending tests of cantilevers prepared by a focused ion beam technique showed good interface bonding between the coating layer and the substrate. Nanoindentation and micropillar compression tests in the cross-section of polished samples show different mechanical responses of each phase. The substrate exhibited the lowest hardness and most ductile deformation under compression, while interfacial Zr 2 Fe and Zr 3 Fe possessed the highest hardness and brittle failure.

Gigax, J. G., Kennas, M., Kim, H., Maier, B. R., Yeom, H., Johnson, G. O., Sridharan, K., & Shao, L.

Interface reactions and mechanical properties of FeCrAl-coated Zircaloy-4 Academic Article